Circuit interrupting means



Dec. 17, 1940 P. B. HOYE CIRCUIT INTERRUPTING MEANS Q SheetS-Sheet 1Filed Feb. 1, 1937 Dec. 17, 1940. P, B, HOYE, 1 2,225,055

CIRCUIT INTERRUP'IING MEANS Filed Feb. 1, 19:57 9 Sheets-Sheet 2 IZia/@7750)":

(Bay fade/15156 70 Dec. 17, 1940. HOYE 2,225,055

CIRCUIT INTERRUPTING MEANS Filed Feb'. 1, 1937 9 Sheets-Shget 3 Dec.17', 1940. P; B. HOYE cmcum INTERRUPTING MEANS Filed Feb. 1, 1937 9Sheets-Sheet 4 C //PC 0/ 7 BREAKER ChQCU/ BE Dec. 17, 1940. P. B. HOYE2,225,055

C IRCUIT INTERRUPTING MEANS Filed F'eb.- 1, 19:57 9 Sheets-Sheet 5 Dec.17, 1940. HOYE 2,225,055

CIRCUIT INTERRUPTING MEANS Dec. 17, 1940. p HQYE 2,225,055

CIRCUIT INTERRUPTING MEANS,

Filed Feb. 1, 1937 9 Sheets-Sheet 8 2y W I Dec. 17, 1940. HQYE 2,225,055

CIRCUIT INTERRUPTING MEANS Filed Feb. 1, 1937 9 ShevtsSheet 9 fig .14!50 fax/aw)".-

Patented Dec. 17, 1940 UNITED STATES.

PATENT OFFICE CIRCUIT INTERRUPTING MEANS Application February 1, 1937,Serial No. 123,325

11 Claims.

My invention relates, generally, to electric circuit interrupters orcircuit breakers, and has particular relation to the construction andoperation thereof.

In order to electrically close a circuit interrupter or circuit breaker,operating devices in the form of solenoid mechanisms and electric motormechanisms are employed. The solenoid mechanisms are provided witharmatures, while the motor mechanisms are arranged to operate eitherdirectly or through suitable reduction gearing. On energization of oneof these mechanisms, the contact members of the circuit breaker areoperated to the closed position through a suitable linkage and they areheld in this position by various types of latching or holding devices.On release of the latching or holding device, the contact members arepermitted to move to the open position under the biasing force ofgravity or of suitable springs or weights, or a combination of thesebiasing forces in order to quickly extinguish any arcs that may be drawnby separation of the contact members while carrying current.

Accordingly, the object of my invention, generally stated, is to providea circuit interrupter or circuit breaker and operating means thereforwhich shall be simple and .efficient in operation, and which may bereadily and economically manufactured and installed.

It is necessary to provide some means for deenergizing the operatingdevice on closure of the circuit breaker. However, it is equallyessential to maintain the operating device energized until the circuitbreaker is operated to the fully closed position where it can be heldclosed by the latching or holding device. When it is recalled that thecircuit breaker is closed with considerable force by the operatingdevice and severe shocks and vibrations result, it will be appreciatedthat a rugged and reliable cut-off mechanism must be provided to effectthe deenerg'ization of the operating device at the proper time.

4 In view of these requirements, an important object of my invention isto provide for deenergizing the operating device employed for closing acircuit breaker at the proper instant when the circuit breaker isoperated to the closed position,

50 and which shall not require close adjustment.

Another important object of my invention is to provide for deenergizingthe operating device of a circuit breaker at the proper instant withoutopening the control circuit therefor.

55 Another important object of my invention is to combine the cut-offmechanism of a circuit breaker with the holding or latching mechanism insuch manner as to deenergize the operating device used for moving thecontact members of the circuit breaker toward the closed position at the1 proper instant and to effect the final movement of the contact membersby the cut-off mechanism, thereby rendering unnecessary an exact timingof the deenergization of the operating device.

In many industrial applications of electric 10 power, the continuity ofpower supply is of utmost importance. In the event of a failure of thepower supply, valuable time may be lost through the enforced shut-downof electrically driven machines and the like. Also, in some industries,such as those in which electric heating devices and electric furnacesare used, a failure of power supply may cause a loss in material beingprocessed or such change in the material being processed as to render itworthless. In such installations, an auxiliary or emergency powercircuit is provided to which the load circuit can be transferred onfailure of the main or preferred power circuit. Therefore, anotherobject of my invention is to provide for quickly and automaticallytransferring a load circuit from a preferred power circuit to anauxiliary power circuit on the occurrence of a fault, such as failure ofpower, on the preferred power circuit.

A further object of my invention is to provide for automaticallytransferring the load circuit back to the. preferred power circuit assoon as the fault on it is removed.

Still another object of my invention is to interlock the controlcircuits of the circuit breakers employed to effect this transfer insuch manner as to prevent the simultaneous closure thereof.

A further object of my invention is to interlock the holding or latchingand cut-off devices of the circuit breakers in such manner as to pre- 0vent this simultaneous operation.

Where transfer circuit breakers are provided for connecting a loadcircuit to an auxiliary power circuit when the main or preferred powercircuit fails, it may be desirable in some cases to interconnect themain and auxiliary power circuits. The auxiliary power circuit may forma part of a power system to which other load circuits may be connected.On failure of power on the auxiliary circuit, these load circuits are,of course, deenergized. However, they can be energized by simultaneouslyoperating both of the circuit breakers which normally are employed fortransferring the main load circuit from the main power circuit to theauxiliary power circuit. The reverse operation may also be true and itmay be desirable to supply power to the main power circuit from theauxiliary power circuit by a simultaneous operation of both of thesecircuit breakers.

Thus, another object of my invention is to provide for automaticallytransferring a load circuit from a main to an auxiliary power circuit onfailure of the main power circuit for example, and for interconnectingthe two power circuits under certain operating conditions.

On the occurrence of a fault on a power circuit, such as a shortcircuit, the circuit breaker which is provided for connecting it to apower source is immediately opened by suitable fault responsive relaysto clear the system of the fault. Operating experience indicates thatfaults of this nature are temporary, and clear themselves in most caseswithin a very short time. The circuit breaker can, therefore, beimmediately reclosed and continuity of power substantially maintaineddespite its temporary interruption. In such case it is highly desirablethat the circuit breaker be immediately reclosed with a minimum outagetime for the circuit. This time is comparatively short and is of theorder of a fractional part of a. second or a few cycles, for examplethree or four, in a 60-cycle system.

0 Therefore, a further object of my invention is to immediately reclosea circuit breaker that has been opened because of the occurrence of afault on the circuit in which it is connected.

Another object of my invention is to open the 5 energizing circuit of avariable impedance device, that is used to control, the functioning of acircuit breaker operating device and to hold it closed, upon theoccurrence of a fault to immediately initiate the reclosure of thecircuit breaker within a fractional part of a second.

As set forth hereinbefore, when a circuit breaker is closed, aconsiderable shock is experienced when the movable contact members areoperated to the closed position. The fixed or stationary contactmembers, cooperating therewith, are ordinarily mounted in tubularinsulators which, in turn, are mounted in the circuit breaker housing.Rod-like conductor members extend through the tubular insulators toconnect the stationary contact members with external bushings and theexternal circuits. Considerable difficulty has been experienced inobtaining a satisfactory means for securely holding the rod-likeconductors in the insulators because of the shock and vibrations thatare set up on closure of the circuit breaker.

Therefore, an ancillary object of my invention is to provide a resilientconnection in the external bushing nut between it and the insulator inengagement therewith.

Other objects of my invention will, in part, be obvious and in partappear hereinafter.

My invention, accordingly, is disclosed in the embodiments thereof shownin the accompanying drawings, and it comprises the features ofconstruction, combination of elements and arrangement of parts whichwill be exemplified in the constructions hereinafter set forth, and thescope of the application of which will be indi- O cated in the appendedclaims.

For a more complete understanding of the nature and scope of myinvention, reference may be had to the following detailed descriptiontaken r in connection with the accompanying drawings,

0 in which:

Figure 1 is a View, in side elevation, of my novel circuit interrupterand operating mechanism therefor, the housing being shown in section;

Figure 2 is a detail sectional View, taken generally on the line 2-2 ofFigure 1;

Figure 3 is a sectional view, taken along the line 33 of Figure 1;

Figure 4 is a detail sectional View, taken along the line 4-4 of Figure5, the motor being shown in outline only;

Figure 5 is a sectional View taken along the line 5-5 of Figure 1;

Figures 6 and '7 show different operating positions of the linkage thatis employed in interconnecting the motor and the movable contact membersof the circuit breaker;

Figure 8 illustrates, diagrammatically, the general arrangement of mynovel reclosing circuit breaker system and connections forsimultaneously operating both of these circuit breakers to provide aninterchange of power between .the main and the auxiliary power circuits;

Figure 9 illustrates, diagrammatically, the circuit connections that maybe employed in practicing my invention in conjunction with the circuitdiagram shown in Figure 8;

Figure 10 illustrates, diagrammatically, a mod ified circuit arrangementfor controlling the transfer system which may be employed in lieu of thecircuit connections shown in Figure 9;

Figures 11 and 12 illustrate, diagrammatically, modified arrangements ofmy novel circuit interrupting means;

Figure 13 illustrates, diagrammatically, how my invention may beembodied in a control system that is energized with direct rather thanalternating current; and

Figures 14 and 15 illustrate the novel features of my circuitinterrupter as applied to a reclosing circuit breaker system.

According to my invention, I provide for closing a circuit breakerthrough a suitable linkage by means of a torque motor that is arrangedto operate through a partial revolution. It will be understood, however,that other suitable energy translating devices may be employed insteadof a torque motor. Since a preferred embodiment of the invention employsa motor of this type, the functioning of my novel circuit interrupterwill be set forth in connection therewith.

The torque motor is energized by operation of a suitable control relaywhich serves to connect it for energization to a suitable currentsource, such as a source of alternating current. The winding of thecontrol relay is connected for energization through a winding on a corethat has associated therewith an armature which is connected to thelinkage and moves together with the movable contact members of thecircuit breaker. When the circuit breaker is in the open position, thearmature is positioned away from the core, and therefore, the impedanceof the winding thereon is relatively low. On energization of the relaywinding and the winding on the core connected in series circuit relationtherewith from a source of alternating current, the control relay isfirst operated to effect the energization of the torque motor. As thearmature approaches the core, the impedance of the winding thereonincreases until, at the time that the circuit breaker is closed, thecurrent flowing therethrough and through the relay winding isinsufficient to maintain the relay in the operated condition. As aresult, the torque motor is deenergized. Sufficient current, however,continues to flow through the winding on the core to hold the armaturein engagement therewith. The circuit breaker is thus held in the closedposition as long as the winding on the core remains energized. As soonas this winding is deenergized, the armature is no longer attracted tothe core, and the movable contact members of the circuit breaker arereleased for operation to the open position.

Generally speaking, the armature and core, and the winding thereonperform three functions. As

the movable contact members approach the closed position, the attractionof the armature to the core is sufficient to effect the final movementthereof, and thus the torque motor is relieved of operating them to thefinal position. It is, therefore, unnecessary to provide an. exactcontrol for the time when the torque motor is deenergized. The secondfunction that is performed is the holding of the circuit breaker in theclosed position until the winding on the core is deener gized. The thirdfunction is the deenergization of the relay winding to such an extentthat its contact members are opened to disconnect the torque motor fromits energizing source. It will now be obvious that I have provided asimple and efficient means for controlling the functioning of a circuitinterrupter which does not depend for its operation upon the opening ofcarefully positioned limit switches and the functioning of mechanicallatches to deenergize the circuit breaker operating mechanism and tohold it in the closed position.

Various embodiments of the foregoing generally described circuit breakeror circuit interrupter will be presently set forth, together with anindication of the manner in which my invention may be employed inconnection with a system for transferring automatically a load circuitfrom a main power source to an auxiliary power source in the event of afault on the main power source. In addition, my invention will also beillustrated in connection with a reclosing circuit breaker system thatis employed for immediately reconnecting a circuit to a power sourceafter a temporary fault thereon has been cleared.

Referring now particularly to Figures 1, 2, 3, 4, and 5, it will beobserved that the reference character 2B designates, generally, acircuit interrupter having a housing 2| through the upper side of whichinsulator bushings or tubes 22 extend for supporting stationary contactmembers 23 in insulated spaced relation. A four pole circuit breaker hasbeen illustrated for use in connection with a three phase four-wirecircuit, but it will be understood that my invention may be practiced byusing a circuit breaker having a different number of poles forconnection in a different circuit. Movable contact members. 24, carriedby rods 25 of insulating material, are provided to bridge the pairs ofstationary contact members 23. 'The rods 25 are carried by a commonsupport member 25 which is channel-shaped, and to which is secured apair of upstanding ears 2'! between which a lever 28 is positioned andsecured thereto by a pin 29. The other end of the lever 28 is secured bya pin 3|! between a pair of support plates 3! that are suitably securedto the upper surface of a top plate 32, which in turn is suitablymounted in the housing 2 I. The contact members 24 are arranged to moveto the position shown bythe broken lines in Figure 3 of the drawingsunder the influence of gravity, and are arranged to be operated intoengagement with the stationary contact members 23 by movement of thelever 28 about the pin 35 as a fulcrum by means which will be presentlydescribed.

In order to movethe lever 28 upwardly about the pin 30 as an axis, apair of toggle joints is provided. An additional toggle joint isprovided for cooperating with the first two toggle joints to hold themovable contact members 24 in the closed position. These toggle jointscomprise what may be generally described as a linkage.

The first toggle joint includes a pair of flat links 35 that are securedto the lever 28 by a pin 35 at one end. At the other end the links 35are secured by a pin 31 to an arm 38 of a cast steel operating member 39which is rotatably mounted on a transverse shaft 45! that extendsbetween frame plates 4| and 42 that are secured to and depend from thetop plate 32, as illustrated more clearly in Figure 2 of the drawings.Integrally formed with the operating member 39 is a pair of arms 43between which a link 44, forming a part of the second toggle joint, issecured by a pin 45. Pivotally mounted on. a pin 45, extending betweenthe frame plate 4| and a frame plate 41 depending from the top plate 32,is a bellcrank 48, one arm of which forms the complementary part of thesecond toggle joint. The bellcrank 48 comprises a pair of spaced. armsbetween which one end of the link 44 is positioned and secured theretoby a pin 49. A roller 55 is mounted on a pin 5| extending through thetwo members forming the bell crank 48 for a purpose which will bepresently set forth.

By means of a pin 52, the third toggle joint is connected to the otherarm of the bellcrank 48. This toggle joint comprises a link 53 which issecured by a pin 54 to a socket member 55 that,

in turn, is pivotally mounted on a pin 55 extend ing between the frameplatesv 4| and 41. The socket member 55 is provided with a socket 51into which an operating lever may be inserted for manually operating thecircuit breaker.

With a View to holding the circuit breaker in the closed position, alink 53 is connected at one end to the pin 54 of the third toggle joint,and, at the other end, by a pin 59 to the tail piece 65 of an armature 6I which is pivotally mounted on a pin 52 that is carried by a core 63.core 63 is mounted on the frame 2 i in any suitable manner, and hasprovided thereon a holding winding 64 which, on energization, serves toattract the armature 6| to the core 63. However, the force that isexerted by the holding winding 64 is not suflicient to attract thearmature 6| to operate the movable contact members 24 to the closedposition. from the full open. position, but it is sufficient to effectthe final closure thereof and to hold them closed when the armature 6|is in close proximity to the core 63. Therefore, it will be understoodthat the armature 6| is movable through the agency of the three togglejoints, together with the movable contact members 24.

As illustrated in Figure 1 of the drawings, the circuit breaker 20 is inthe closed position. In this position, the third toggle joint comprisingthe link 53 and the socket member 55 are nearly in alignment. That is,the pins 52, 54 and 56 are very nearly positioned in a straight line.Therefore, the force that is required to be exerted by the armature 5|,as attracted by the winding 64, is only that which is necessary toprovide the slight component of the total force that is required to holdthe movable contact members The 24 in the closed position. Moreover,when the holding winding 64- is deenergized, this slight component offorce no longer exists, and the third toggle joint is no longerrestrained. The movable contact members 24 are then free to move to theopen circuit position.

The movable contact members E i are operated toward the stationarycontact members 23 initially by a motor 68 that is suitably mounted inthe frame 2!. The motor 83 is preferably a torque motor of the seriestype, the shaft til of which is rotated only through a partialrevolution to efiect the movement of the contact members 24 from theopen to the closed position. Mounted on the shaft 65% and for rotationtherewith is a cam member 79. As illustrated, the cam member :0 iscircular in outline and is eccentrically mounted on the shaft 69. Acut-away section ll is provided in the body of the cam member ill inorder to so position the center of gravity of the cam member that itwill be readily biased by gravity to the position shown in Figure 1 ofthe drawings as soon as the motor 68 is deenergized. A rubber bumper F2is provided with a suitably curved surface, and is positioned in thepath of movement of the cam member 19 as it is restored to its normalposition to cushion the shock. The external surface of the cam memherIt! is arranged to engage the roller 59 for operating the circuitbreaker to the closed position. A circular opening 13 is provided in theframe plate 4! to permit inspection and adjustment of the linkage andthe various parts cooperating therewith.

In Figures 6 and '7 of the drawings, I have illustrated the positions towhich the linkage interconnecting the motor 68 and the movable contactmembers 24 is operated. Figure 6 shows the linkage with the circuitbreaker closed, and Figure 7 shows the linkage with. the circuit breakeropened. In the latter position, it will be observed that the roller 58is in engagement with the outer surface of the cam member Ill that isclosest to the shaft 59. When the motor 68 is energized and. the shaft69 rotates in a clockwise direction carrying with it the cam member Ill,the roller 5b is moved upwardly, thereby moving the second toggle jointformed by the link 44 and one arm of the bellcrank 58 toward itsposition as shown in Figure 6 of the drawings. At the same time, thefirst toggle joint formed by the links 35 and the operating member 39 ismoved to the right to lift the lever 28. When the cam member 15 isrotated to the position indicated by the broken lines in Figure 6 of thedrawings, the pins 45, 49 and it will nearly be in alignment as will bethe pins 36, t5 and M].

only a small component of force is required to be exerted by the thirdtoggle joint comprising the link 53 and the socket member 55 to hold themovable contact members 2 1 in the closed position.

By means which will be presently described, the motor B3 is deenergizedas the cam member '40 approaches the position shown by the broken lines,and the cam member ill returns to its original position under theinfluence of gravity and is stopped by the rubber bumper 12. As long asthe winding 64 remains energized and the third toggle joint isrestrained by the armature 6|, the circuit breaker will remain in theclosed position. On deenergization of the holding winding 6%, thearmature 6| will be released, as previously set forth, thereby releasingthe linkage and permitting the circuit breaker to be operated to theopen position under the influence of gravity and under the influence ofbiasing springs, if such springs are employed.

With a View to limiting the travel of the movable contact members 24 inthe open position, a boss 15 is provided on the upper end of the arm 38,as illustrated more clearly in Figure 4 of the drawings, and it isarranged to engage a wooden plug 16 that is carried at the right handend of an adjustable stop member Tl. The left hand end of the stopmember 11 is threaded into a suitable lug 18 that depends from the topplate 32 and is secured in the desired position by a lock nut '39. If itis desired to hold the circuit breaker in the closed position While theoperating mecha nism is being repaired or adjusted, the lock nut l9 canbe loosened and the stop member l1 rotated until the plug 16 engages theboss 15 in its position as shown in Figure 4. The holding winding 64 maythen be deenergized without opening the circuit breaker.

As indicated hereinbefore, a considerable shock is experienced by thestationary contact members 23 on engagement therewith by the movablecontact members 24. As a result of repeated impacts, the sealedconnection between the stationary contact members 23 and the lower endsof the insulator bushings 22 may be broken. Moisture may then bepermitted to enter the interior of the housing 2| and to contaminate theoil therein which surrounds the contact members and in which arcs aredrawn when the circuit is opened under load. In order to insure that thesealed connection will not be broken, the construction illustrated moreclearly in Figure 3 of the drawings has been provided.

As illustrated in Figure 3. one of the insulator bushings 22 has beenshown in section. The stationary contact member 23 has connected theretoa rod-like conductor 82 that extends upwardly through the bushing 22 andhas threaded on its upper end a bushing nut 83. A gasket 84 of asuitable compressible material is positioned between the lower end ofthe bushing 22 and the upper surface of the stationary contact member23. As originally installed, the bushing nut 83 is turned on the upperend of the conductor 82 against a flange 85, integrally formed near theupper end of the bushing 22, compressing the gasket 84 and providing thedesired sealed connection.

If the bushing nut 83 is formed as a solid member of copper andinternally threaded, the desired sealed connection will be provided,merely by tightening the bushing nut 83.

jected to several impacts during operation, the gasket 8 becomes furthercompressed, and no corresponding tightening action takes place withrespect to the nut 83 unless it is manually tightened. As a result, thesealed connection may be broken and moisture may enter as previouslydescribed.

With a view to automatically taking up this slight slack that is causedby the compression of the gasket 84, I have modified the lower end ofthe bushing nut 83 by providing an internal groove 85 near the lowerend, and an external groove 8? immediately thereabove by a suitableturning operation. A certain degree of flexibility and resiliency is nowprovided in the lower end of the bushing nut 83 while still maintaininga complete engagement with the upper surface of the flange 85. When thebushing nut 83 is originally installed, it is tightened with sufficienteilort However, after the stationary contact member 23 has been subtocompress the resilient lower end thereof slightly. Sufficient resiliencyis thereby provided to maintain the sealed connection despite repeatedtegrally formed fingers 88 that are surrounded by garter springs 89. Aplug-like terminal member 90 is provided for interfitting between thefingers 88. A suitable opening Si is provided in the plug member 90 intowhich a circuit conductor may be secured, as by soldering, as will bereadily understood. An insulator sleeve 92 surrounds the plug member 00,and extends over the upper end of the insulator bushing 22, asillustrated.

Thus far I have described in detail the construction and functioning ofa circuit breaker which operates as a single unit. It will be understoodthat the circuit breaker may be arranged for individual operation inconjunction with a suitable control mechanism, and that it may bearranged to function in connectionwith a second circuit breaker of likeconstruction for transferring a load circuit for energization from amain or preferred power circuit to an auxiliary or emergency powercircuit. The latter type of arrangement will first be described with aview to illustrating the novel features .of my invention as applied tosuch a system.

When it is desired to insure a continuity of power on a load circuit, itis customary to provide an alternate or emergency power circuit inaddition to the main or normal power circuit and to provide thenecessary switching devices for automatically transferring the. loadcircuit from one power supply to the other as the case may be. Theauxiliary or emergency supply circuit may form a part of a singlegenerating system, and it may be so arranged-that it'would be unaffectedby the occurrence of a fault on the main power circuit. Again, theauxiliary power circuit may be energized from an entirely separatesource of power for the purpose of insuring the highest degree ofreliability.

For the purposes of description, the alternate power circuit isdescribed as an emergency or auxiliary power circuit. However, thiscircuit may be employed to supply other loads during the normal courseof operation. In like manner, the main or normal power circuit may alsobe employed to supply other loads than the particular load underconsideration which may be supplied fromeither power circuit. On thefailure of power on either of these circuits, it may be desirable toprovide for so operating the transfer switching equipment that eithercircuit may be energized from the other one so that all of the loadcircuits connected thereto may be energized. For this purpose I haveprovided the circuit arrangement and system that is discloseddiagrammatically in Figure 8 of the drawings.

As shown in this figure, a preferred power circuit, shown generally at95, is provided comprising a neutral conductor N and line conductors A,B and C. While a three phase four-wire system is illustrated herein, itwill be understood that other types of systems come within the scope ofmy invention. The preferred power circuit is connected by a circuitbreaker 96 to a polyphase generator 91 which is arranged to generate acommercial frequency, such as 60 cycles. A load circuit .28 is arrangedto be energized from the preferred power circuit at on operation of acircuit breaker 8S.

The auxiliary power circuit, shown generally at WI, and comprising aneutral conductor N and line conductors A, B and C, may be connected forenergization by a circuit breaker I02 to a polyphase generator I03 thatmay be similar in its operating characteristics to the generator 91. Aload circuit, shown generally at I04, may be energized by a circuitbreaker I05 from the auxiliary power circuit IOI.

The reference character I516 designates, generally, a common loadcircuit comprising a neutral conductor N and line conductors A", B" andC which are arranged to be connected to the corresponding conductors ofthe preferred power circuit $5, or of the auxiliary power system IN bythe operation of circuit breakers I01 and I08.

The circuit breakers 96, 99, I02 and I05 may be of the type disclosedherein, or they may be of any other suitable type, well known to thoseskilled in the art. I08 are preferably constructed as disclosed hereinand controlled in the manner which will be presently set forth.

Under normal operating conditions, the common load circuit I08 will beenergized from the preferred power circuit 95 as energized by thegenerator 97. For this purpose the circuit breakers 96 and I01 will beclosed. In addition, the load circuit 98 will be energized when thecircuit breaker 99 is closed. The load circuit I04 will be energizedfrom the auxiliary power circuit IIlI when the circuit breakers I02 andI05 are closed.

Assuming now that some fault occurs in the generator 91 or the circuitsconnected thereto that may be cleared by opening the circuit breaker 96,the preferred power circuit 95 will be deenergized and the circuitbreaker I01 will be automatically opened and the circuit breaker I08will be automatically closed to transfer the common load circuit I06 forenergization to the auxiliary power circuit IOI. If no further operationtakes place, the load circuit 98 will be deenergized because of thedeenergization of the preferred power circuit 95. However, if means areprovided for closing the circuit breaker I01, which forms a part of theautomatic transfer system, this load circuit 98 can still be energized,in this case, from the generator I03. In like manner, on failure of thegenerator I03, the circuit breaker I08 may be operated to maintain poweron the auxiliary power circuit WI and to energize the load circuit I04.Thus, it will be observed that the transfer system may be arranged toserve a dual purpose; first, to maintain power on the common loadcircuit I06, and second, to maintain the load circuits connected to thepreferred and auxiliary power circuits energized under certain operatingconditions. It will be understood that the first function will beperformed automatically while the latter function will be performedunder manual control, since it is undesirable to interconnect thepreferred and auxiliary power circuits when both of the generators 91and I03 are operating because of the necessity of synchronizing them.However, as is well known to those skilled in the art, suitablesynchronizing apparatus may be provided so that the generators 91 andI03 may be interconnected by operation of the circuit breakers I01 andI08, which form a part of the automatic transfer system. The controlcircuits for effecting the foregoing described operation of the circuitbreakers I01 and I08 are illustrated in detail in Figure 9 of thedrawings.

The circuit breakers I01 and In this figure I have illustrated thecircuit breakers It! and I08 in diagrammatic form, together with theoperating mechanism therefor, each of which is preferably constructedand arranged as shown in Figure 1 of the drawings and describedhereinbefore. Insofar as practical, the same reference characters willbe employed in order to indicate the various parts that are identical.The circuit breaker I8! is arranged to be closed by the series motor 68having an armature 68A and a series field winding 68F. In like manner,the circuit breaker IE8 is arranged to be operated to the closedposition by a series motor 68' having an armature 88A and a fieldwinding SB'F. The motors 68 and 88' are arranged to be energized frompower transformers H and III having primary windings H2 and H3 that areconnected respectively for energization between the neutral conductorand one of the line conductors of the preferred and auxiliary powercircuits 95 and IQI. The secondary windings H2 and I I5 of thesetransformers are commonly connected to a control bus H6, while the otherterminals are connected to control busses H8 and Hi). In one commercialembodiment of my invention, the secondary windings II4 and H5 arearranged to supply a control voltage of 220 volts. Of course othercontrol voltages may be employed if desired.

In order to effect the connection of the motor 68 to the conductors H3and H8, a control relay I is provided having an operating winding I20wand make contact members I20a. In like manner, a control relay I2I isprovided for effecting the energization of the motor 68. This relay isprovided with an operating winding I2Iw and make contact members I2Ia.Single pole double throw switches I22 and I23 are provided forselectively connecting the motors 68 and 68 for energization to thecontrol busses H8 and I! 9. When the switch I22 is operated to its upperposition, the motor tllwill be energized from the conductors H8 and II8.When it is operated to its lower position, the motor 68 will beenergized through conductor I24 from the conductors H6 and II9.Likewise, when the switch I23 is operated to its lower position, themotor 68 will be energized through conductor I25 from conductors IIS andIIE.

With a view to interlocking the circuit breakers I01 and H28 for thepurpose of preventing simultaneous operation thereof, auxiliary breakcontact members Him and Iflia are arranged to be operated therewith.When the circuit breakers I01 and IE8 are in the open positions, thesecontact members are closed. However, on operation of one of thesecircuit breakers to the closed position, its auxiliary contact membersare opened and the control circuit for effecting the energization of theother circuit breaker is normally held open.

As has been indicated hereinbefore, it is de sirable to provide forautomatically transferring the load circuit I06 from the preferred powercircuit 95 to the auxiliary power circuit MI in the event of a faultoccurring on the preferred power circuit. This fault will ordinarily beof the nature of a loss of power on one or more of the phases. For thepurpose of detecting the failure of voltage on one or more of the phasesof the. preferred power circuit 95, voltage relays I28, I29 and I30 areprovided, each of which is individual to one of the phases, asindicated. Each of the voltage relays is provided with break contactmembers I28a, I29a and I30a which are connected in parallel circuitrelation for a purpose which will be apparent hereinafter. These relaysare also provided with make contact members I281), I282) and I 30b.These contact members are connected in series circuit relation for apurpose which will also be set forth hereinafter. Operating windingsI28w, I20w and I30w are provided which are connected for individualenergization to the secondary windings I32, I33 and I34 of potentialtransformers I36, I3! and I38, the primary windings I40, I II and I42 ofwhich are commonly connected for energization to the neutral conductor Nand for individual energization from the line conductors A, B and C, asillustrated.

While voltage relays I28, I29 and I30 have been illustrated forconnection to the preferred power circuit 95, it will be understood thata similar set of voltage relays may be provided and connected to theauxiliary power circuit IOI for the purpose of making this the preferredpower circuit, if such operation is desired. However, since theillustration of these connections would mean merely a duplication of theconnections already illustrated and described, and, further, since theconnection thereof will be apparent to those skilled in the art, thisadditional feature has not been shown in detail herein.

For the purpose of interconnecting the preferred and auxiliary powercircuits 95 and IOI,

control switches I44 and I45 are provided. When these switches areclosed, as will be described hereinafter, the system will function asset forth hereinbefore in connection with the description of the circuitillustrated in Figure 8 of the draw- 7 mgs.

In describing the operation of the transfer system shown in Figure 9, itwill be assumed that the preferred and auxiliary power circuits 95 andIOI are energized, and that the switches I22 and I23 are operated totheir upper positions. It will also be assumed that the control switchesI44 and I45 are in the open positions. Under these operating conditions,the windings of the voltage relays I28, I29 and I30 will be energized,thereby closing the make contact members I281), I291) and I302). Theoperating winding of the control relay I20 will then be energized toconnect the motor 68 for energization across the control bus representedby the conductors H8 and II 6 by the closure of contact members I20a.

The circuit for energizing the operating winding' I20w of the controlrelay I20 may be traced from the energized conductor II8 through theswitch I22, operating winding I20w, holding winding 64, break contactmembers I08a of the circuit breaker I08, and series connected contactmembers I282), I29?) and I30b to the energized conductor II6.

It will be recalled that the armature 6I is moved toward the core 63,Figure 1, and toward the holding winding 64 thereon when the motor 68rotates the cam 70 to operate the toggle linkage by engagement with theroller 50. When the circuit breaker I0! is in the open position and thearmature BI is at its furthest position from the winding 64, theimpedance of this winding will be a minimum, and consequently suflicientcurrent will flow through it to energize the operating winding I20w ofthe control relay I20 and close the contact members I20a. As the circuitbreaker I01 reaches the closed position, the impedance of the holdingwinding 64 gradually increases because of the movement of the armature6|. On engagement of the ar-' mature 6| with the core 63, the impedanceof the holding winding 64 increases to a much higher value, andconsequently there is a decrease in the current flowing through it andthrough the series connected operating winding I20w of the control relayI20. While current still continues to flow through the winding I20w, itis not suflicient to hold the contact members I200. closed and, as aresult, the motor 68 is deenergized. The control relay I20 is soconstructed that a diminution in energizing current of 50% of theinitial value will cause the contact members I20a to be opened. Thevariation in impedance of the holding winding 64 is such as to cause adecrease in the current flow therethrough of approximately 90% of theinitial value. While the necessary change in its impedance is of theorder of l to 2 to effect the deenergization of the control relay I20 tothe necessary extent, it actually changes in the ratio of 1 to 10. Thesefigures are taken from a commercial embodiment of my invention, but itwill be understood that other ratios may be emiployed without departingfrom the scope of my invention.

As the armature 6| approaches the winding 64, sufiicient force isexerted on the toggle linkage, as set forth hereinbefore, to effect thefinal closure of the circuit breaker I01. Therefore it is unnecessary toadjust with a high degree of accuracy the functioning of the controlrelay I20 in opening the energizing circuit for the motor 68.Furthermore, because of the arrange- :ment and construction of thelinkage between the armature BI and the circuit breaker I01, only a veryslight force need be exerted to hold it in the closed position. Thisforce is provided by the greatly diminished current still flowing Ithrough the holding winding 64, as will be readily understood.

Since the holding winding 64 is energized from the preferred powercircuit 95, it inherently operates as an under-voltage device that willautomatically release the circuit breaker I01 for movement to the openposition on decrease in voltage on the preferred power circuit 95 to apredetermined value. 'For the particular circuit connection shown, adecrease in voltage between 1 the line conductor A and the neutralconductor N to a predetermined value will eirect a sufiicientdeenergization of the holding winding 64 as to release the circuitbreaker I01. While this control is not as sensitive as that which isprovided 'by the voltage relays I28, I29 and I30, still use may be madeof it if desired.

Assuming now that the voltage fails on one or more of the lineconductors of the preferred power circuit 95, for example the lineconductor B, the operating winding I29w of the voltage relay I29 will bedeenergized, opening make contact members I29b and closing break contactmembers I29a. The previously traced energizing circuit for the holdingwinding 64 and "the operating winding I20w of the control relay I20 willthen be opened at contact members I29b and the circuit breaker I01 willbe released for movement to the open position. At the same time atcontact members I29a a circuit will be completed for effecting theenergization of the operating winding I2Iw of the control relay I2I tocomplete an energizing circuit at its make contact members I2Ia forconnecting the motor 68 for energization across the control buscomprising the conductors H6 and H9.

This circuit may be traced from the energized conductor II6 throughcontact members I29a, auxiliary contact members I01a, which will beclosed when the circuit breaker I01 is operated to the open position,holding Winding 64', operating winding I2Iw, and switch I23, to theenergized conductor H9.

The circuit breaker I 08 will be closed by the motor 60 in a mannersimilar to that described for the closure of the circuit breaker I01. Inlike manner, the current flowing through the operating winding I2 Iwwill be decreased as the circuit breaker I08 app-roaches the closedposition, and the motor 68' will be deenergized. The circuit breaker I08will be held in the closed position by the continued energization of theholding winding 64, even though the current flow therethrough is reducedto the minimum normal value.

It will now be obvious that as long as the circuit breaker I531 remainsin the closed position, the previously traced circuit for eifecting theclosure of the circuit breaker I 08 cannot be completedbecause theauxiliary contact members Ilila are open. In like manner, as long as thecircuit breaker I08 remains in the closed position, its auxiliarycontact member IOBa are open and the automatic operation of the circuitbreaker I01? is prevented.

Assuming now that the line conductor B of the preferred power circuit 95is again energized with the required voltage, the voltage relay I29 willbe operated to open at contact members wile the energizing circuit forthe holding winding G l, and the circuit breaker I08 will be releasedfor movement .to the open position. At contact members I291) a circuitwill be completed, as previously traced, for again effecting theoperation of the circuit breaker I01 to connect the load circuit I06 forenergization to the preferred power circuit 05.

If it is desired to effect the simultaneous operation of both of thecircuit breakers I01 and I08, one or .the other of .the switches I 44 orI45 may be closed, depending upon which one of the circuit breakers isalready closed. Assuming that the circuit breaker I01 is closed and itis desired to close the circuit breaker I08, the switch I45 is closed toconnect the holding winding 64' and the operating Winding I2Iw of thecontrol relay I 2! for energization directly across the control busformed by the conductors H6 and I19. This circuit is obvious and willnot be traced. The closure of the circuit breaker I will take place asdescribed hereinbefore.

In like manner, if the circuit breaker I 08 is closed and it is desired.to close the circuit break- ,er I01, the switch I44 may be closed. Acircuit is then completed for directly energizing the operating windingIZtw of the control relay I20 and the holding winding 64 from theconductors H8 and I I0, thereby shunting the auxiliary contact membersI08a of the circuit breaker I08 and the make contact members of thevoltage relays I28, I29 and I30.

While I have shown a system in Figure 9 of the drawings for operatingthe circuit breakers I01 and W8 as an automatic transfer system, it willbe understood that these circuit breakers may be arranged forindependent operation. That is, the auxiliary contact members I01a andIda may be omitted together with the voltage relays I23, I29 and I30.The circuit breakers I01 and I03 may then be operated independentlyunder the control of the switches I44 and I 35. In addition, as will behereinafter set forth, suitable fault responsive relays may be providedfor operating in conjunction with the circuits completed by the switchesI M and M5 to automaticaliy open the circuit breakers It! and I 58 onthe occurrence of a fault on the circuits in which they are connected.

It will now be apparent that when the holding winding 64, operating as avariable impedance device in conjunction with the armature SI, is used,no provision need be made for opening contact members when the circuitbreaker controlled thereby reaches the closed position. It isunnecessary to take into consideration the effect of jars and vibrationson such contact members that are set up when the circuit breaker isclosed. Moreover, it is unnecessary to provide complicated latchmechanisms that may be likewise affected by the shocks and jars, sincethe holding winding ti operates not only as a, cut-off mechanism butalso as a holding mechanism, and at the same time it provides an addedforce for effecting the final closure of the circuit breaker associatedtherewith.

In Figure 10 of the drawings I have illustrated a modified circuitarrangement to provide the interlocking feature between the circuitbreakers III? and I68 without requiring the use of the auxiliaryswitches IBM and Wild. The interlocking feature is obtained byconnecting the holding windings EM and 64 in series circuit relation.The remaining circuit connections may be identical with those shown inFigure 9, eX-' cept for the provision of the control switches ms andI55.

In operation, assuming that the circuit breaker Ii'Ii has been closed,the impedance of the holding winding Iii will be so great thatsufficient current would not be permitted to flow through the operatingwinding I2Iw of the control relay I2I to eiTect the energization of themotor 68'. In like manner, if the circuit breaker illil is in the closedposition, the impedance of the holding winding (54' is so high thatsufficient current would not be permitted to flow through the operatingwinding I25w of the control relay iii-El to effect the energization ofthe motor The automatic transfer of the cornmon load circuit I55 fromthe preferred power circuit 35 to the auxiliary power circuit IIBI onthe occurrence of a fault on the preferred circuit will take Place asdescribed hereinbefore, as well as the re-transfer to the preferredpower circuit on removal of the fault therefrom.

It may be desirable to provide for mechanically latching a circuitbreaker in the closed position that is operated to this position by theoperating device described hereinbefore. For this purpose the circuitconnections and construction illustrated in Figure 11 of the drawingsmay be employed. As there shown, a circuit breaker I55 is provided forconnection in a circuit represented by the conductors X and Y. For thepurposes of illustration only, a two pole circuit breaker is shown. Thecircuit breaker I55 may be operated to the closed position by the motor65, which is arranged to rotate the cam I5 as described hereinbe'fore.The armature GI and winding 64 associated therewith may also beprovided, but in this embodiment of my invention, its holding functionis not required.

The operating mechanism of the circuit breaker I55 may be provided witha tooth I5I that is arranged to cooperate with a pawl I52 as biased by acompression spring I53. When the circuit breaker I50 is operated to theclosed position by the motor 58, the pawl I52 is positioned underneaththe tooth I51 and holds the circuit breaker in the closed position.Obviously the circuit breaker I50 may be released by manually moving thepawl I52 from engagement underneath the tooth I5I, or suitableelectrical means may be provided for withdaawing it. The circuit breakerI50 is also provided with break contact members I50a, the function ofwhich will presently be apparent.

The motor 68 may be controlled by a control relay, shown generally atI54, and which is provided With an operating winding I54w and makecontact members I5 ia and I541). A manually operable control switch I55is provided for connecting the control mechanism for energization to thesecondary Winding I56 of a power transformer I51, the primary windingI58 of which may be connected for energization to the conductors X andY.

In operation, the control switch I55 is closed, thereby completing anenergizing circuit through the break contact members I5Ila for theoperating winding I54w and the winding 64 from the secondary winding I56of the transformer I51. At contact members I542) a circuit is completedfor energizing the motor 68, and the cam I is rotated thereby to closethe circuit breaker I55.

At contact members I550. the previously traced energizing circuit forthe operating winding M5420 is opened. However, at contact members I540a holding circuit is provided which maintains this energizing circuitintact. It will be obvious that it is unnecessary to provide for theopening of the contact members IEla at a precise instant after thecircuit breaker I50 is operated toward the closed position. It is merelynecessary to provide for opening these contact members at some timeafter the circuit breaker I58 is operated toward its closed position andbefore it reaches this closed position.

The impedance of the winding 54 is increased by movement of the armatureBI toward it, as previously described, and, when the circuit breaker I50is in the closed position, this impedance value is sufliciently high toreduce the current flowing through the operating winding I5 iw to suchan extent that the contact members controlled thereby are opened. Atcontact members I542) the energizing circuit for the motor 58 is opened,and the cam returns to its original position. At contact members I550.the holding circuit for the operating winding I54w is opened, and thiswinding and the winding 64 are deenergized. It will now be apparent thatno current flows through the windings I54w and 64 as long as the circuitbreaker I50 remains closed. In this case the circuit breaker I5!) isheld closed by the mechanical latch comprising the tooth I5I and theassociated pawl I52.

In Figure 12 of the drawings I have illustrated, in a diagrammaticmanner, the arrangement of the linkage shown in Figure 1 for operatingthe circuit breaker I50 to the closed position by the motor 68 and forholding it in this position by the continued energization of the winding64. As previously described, the motor 68 is arranged to rotate the camI0 in engagement with the roller 50 for operating the linkage in suchmanner as to close the circuit breaker I53. In this embodiment of theinvention, the control relay I may be employed, having its operatingwinding I'Eflw connected in series circuit relation with the holdingwinding 64 on the core 53.

instead of the armature 6| being arranged to directly hold the pin 54interconnecting the link 53 and the socket member 55, forming the thirdtoggle joint, in a predetermined position, a latch member I60 isprovided and is mechanically connected to the armature 6|, asillustrated. A tension spring I6I is provided for biasing the latchingmember I00 in a counterclockwise direction about its pivot point. Theupper end of the latching member I60 is provided with an inclinedsurface I62 that is arranged to engage the pin 54.

On operation of the control switch I55 the control relay I20 is operatedto energize the motor 66 and move the circuit breaker I toward itsclosed position through the linkage. The armature 6I is attracted towardthe core 63, but it is prevented from immediately moving into engagementtherewith because of the engagement of the inclined surface I62 of thelatch member I60 with the pin 54. When the circuit breaker I5!) isoperated to the closed position, the pin 54 has moved downwardly alongthe inclined surface I62 until the recessed underside I63 is reached, inwhich position the armature'fil is permitted to move toward the core 63,carrying with it the latching member I60 against the biasing force ofthe spring I6I. The impedance of the winding 64 correspondinglyincreases, and the current flowing through the operating winding I20wdecreases to such an'extent that the contact members 120a are permittedto move to the open position. The motor 68 is deenergized,

but the circuit breaker I50 is held in the closed position by the latchmember I60 as long as the holding winding 64 remains energized. As soonas the control switch I55 is operatedto the open position, the holdingwinding 64 is deenergized, and the spring I6I operates the latch I torelease the pin 54. The circuit breaker I50, is then permitted to moveto the open position.

In some commercial installations, it'is preferable to operate'thecontrol mechanism for the circuit breakers from direct current ratherthan to utilize the alternating current from the circuits in which thecircuit breakers 'are connected. For this purpose, the circuitconnections shown in Figure 13 may be employed. As there shown, asuitablesource of direct current, such as a,

battery '60, is provided for energizing a control bus comprisingconductors I6I and. I62 with direct current. The series motor 68 isarranged to operate the cam I0 to close the circuit'breaker I50.

It will be obvious thatthe circuit breaker I50 may be operated as asingle unit, or it may be operated in conjunction with another circuitbreaker to provide an automatic transfer system such as that shown inFigure 9 of the drawings.

As I have illustrated the embodiment of my invention in Figure 13 foruse in such a system, the circuit breaker I50 is used in place of thecircuit breaker I01 shown in Figure 9 of the drawings. The voltagerelays I28, I29 and I30 could then be used, and the make contact membersof these relays have been illustrated together with the auxiliarycontact members I08a of the circuit breaker I08 to indicate how thesystem may be arranged for automatic transfer operation.

The motor 68 is arranged to be energized by contact members I63 that areclosed by a suitable bridging contact member I 64 that is carried by asuitable insulating member I65 on an auxiliary armature I66 which ispivoted at I61 on a core I68. A Winding I69 is positioned around thecore I68, as illustrated, and may be energized either by the controlswitch I55, or by the control circuit formed by the make contact membersof the voltage relays and the auxiliary contact members of theassociated transfer circuit breaker.

The circuit breaker I50 is held in the closed position by a mainarmature I10 that is pivoted at "I to the core I60 and connected by alink I12 to the pin 54.

In operation, on energization of the winding I69 the auxiliary armatureI66 is attracted toward the core I68 against the biasing force of aspring I13, and contact members I63 are bridged by the bridging contactmember I64. The motor 68 is then connected for energization between theconductors I6I and I62. While the armature I10 is attracted toward thecore I68 fiuence of the spring I13 to open the contact members I 63 anddeenergize the motor 68. As long as the winding I69 remains energized,the main armature I10 remains attracted thereby and the circuit breakerI50 remains in the closed position. On deenergization of the windingl69, the'main armature I10 is released and the circuit breaker I50 ispermitted to operate to the open position, as will be readilyunderstood.

As the main armature I10 approaches the core I68, the increasedattractive force exerted thereon assists the motor 68 in operating thecircuit breaker I50 to the final closed position. Thus, it isunnecessary to accurately adjust the particular instant in this cycle ofoperation when the contact members I63 are opened and the motor 68 isdeenergized.

The arrangement and construction of my novel circuit interrupterforreclosing purposes are illustrated diagrammatically in Figure 14 ofthe drawings. As there shown, the circuit breaker I50 is arranged tobeclosed by the motor 68 on rotation of the cam 10. The holding winding64, associated with the armature 6|, is connected in series circuitrelation with the operating winding I20w of the control relay I20 asdescribed hereinbefore.

For the purpose of automatically opening the circuit breaker I50 on theoccurrence of a fault.

on the circuit in which it is connected and for immediately reclosingit, an auxiliary control relay, shown generally at I15, is providedhaving I contact members I15a connected in series circuit whichare'connected to eifect the energization of the operating Winding I15wfrom the secondary Winding I56 01 the transformer I51. The

relay I16 is provided with an operating winding I16w that is connectedfor energizationacross the terminals of a winding I11 of a currenttransformer that is associated with the line conductor Y.

The circuit breaker Ifit is initially closed by operation of a controlswitch I18, and it is held closed by the holding winding 64 in themanner described hereinbefore. On the occurrence of a predeterminedoverload, sufficient current flows through the winding Ilfiw of theovercurrent relay I'IB, and its contact members I'IBcL are closed toeffect the energization of the operating winding II5w of the auxiliarycontrol relay I15. The energizing circuitfor the holding winding 54 isopened at contact members I'I5a, and the circuit breaker I50 ispermitted to operate toward the open position. As soon as the circuit iscleared, the winding I'Ifiw is no longer energized, and contact membersI'Ifia are opened. Contact members I'I5a of the auxiliary control relayI75 are immediately reclosed to reestablish the control circuit throughthe holding winding 64 and the operating winding I2iiw of the controlrelay I20. The motor 68 is then energized to reolose the circuit breakerI50.

It will be obvious that the system may be so adjusted that it will beunnecessary for the circuit breaker I50 to be operated to the full openposition. That is, the motor 68 may be energized sufficiently soon afterthe circuit breaker starts to move to the open position to cause the camvmember I to engage the roller 50 before the latter is operated to thefull open position. Thus, the circuit may be reclosed within a veryshort period of time, and it may even be closed within one cycle ofGO-cycle current.

If the fault persists on the circuit, the foregoing reclosing cycle willbe repeated. This pumping action may be prevented by any sui able meanswell known to thoseskilled in the art, and will not be described indetail herein. It will be obvious, however, that my novel circuitinterrupter is inherently well adapted for functioning in connectionwith a reclosing circuit' breaker system.

In Figure 15 of the drawings, I have illustrated another embodiment ofthe reclosingsystem illustrated in Figure 14 and described hereinbefore.In this embodiment I have omitted the auXiliary'control relay H5 and theovercurrent relay I76 as such. Instead I have provided a relay,.showngenerally at I30, which operates in a manner similar to thevariable impedance device formed by the armature 6| and the holdingwindingIM. This relay comprises a winding I8I which is connected forenergization to the current transformer winding III that is associatedwith the line conductor Y. A second winding I82 is provided on the relayI80, and it is connected in series circuit relation with the holdingwinding 64. Armatures I83 and I84, connected by a link I05, areassociated respectively with the windings I8I and I82.

The circuit breaker I50 is initially closed by operation of the controlswitch I'IB. At this time the armature I84 occupies a position withrespect to the winding I82 such that the impedance of this winding is aminimum, and consequently the cycle for energizing and deenergizing themotor 68 takes place. The circuit breaker I50 is held in the closedposition by the continued energization of the holding winding 64. On theoccurrence of a fault, such as a short circuit, on the circuit in whichthe circuit breaker I50 is connected, sufficient current flows throughthe winding I8I to attract the armature I83 and to move the armature I84to a position within the winding I82. In this position, the impedance ofthe winding I82 is materially increased and the circuit is soproportioned that this increase in impedance is suihcient to furtherdecrease the current flowing through the holding winding 64 to such anextent that it is no longer capable of attracting the armature 6|. As aresult, the circuit breaker I50 is permitted to operate to the openposition.

As soon as the circuit breaker I50 has operated to this position, thewinding I8I is deenergized and the armature I84 moves out of the windingI52. The impedance of this winding is correspondingly decreased, and theclosing and holding cycle takes placefor operating and holding thecircuit breaker I50 in the closed position. As long as the faultpersists, the circuit breaker I50 will continue to be opened and closed.Suitable anti-pumping means may be provided for limiting the number ofreclosures to one or to any desired number.

t will be obvious that the mechanical trip feature shown in Figure 11 ofthe drawings may be incorporated in either of the systems shown inFigures '14 and 15 of the drawings. With particular reference to Figures11 and 14, it willbe obvious that the over-current relay II6' can beconnected to control a tripping winding associated with the pawl' I52 torelease the mechanical holding mechanism rather than to interrupt thecurrent flowing through the holding winding 64, as in Figure 14.

Since it is obvious that certain further changes may be made in theabove constructions and different embodiments of' the invention may bemade without departing from the scope thereof,

-it is intended that all matter contained in the foregoing descriptionor shown in the accompanying drawings shall be interpreted asillustrative and not in a limiting sense.

I claim as my invention:

1. In a circuit interrupter, in combination, relatively movable contactmembers for opening and closing an electric circuit, motor means foroperating said contact members to the closed position, a control'relayanda winding therefor for controllingthe energization of said motormeans, a variable impedance device disposed to operate together withsaid contact members and a winding therefor, and circuit means forconnecting said windings in series circuit relation and to analternating current source, the impedance of said device beingrelativelylow'when said contact members are in the open position andrelatively high when they are in th closed position, whereby saidcontrol relay is'operated to deenergize said motor means.

2. In a circuit interrupter; in" combination,

relatively movable contact members for opening and closing an electriccircuit, motor means'for operating said-contact members to the'closedposition, a control relay and a winding therefor for controlling the.energization of saidmotor means, a variable impedance. device disposedto operate together with saidcontact members'and a winding therefor,circuit means for connecting said windingsin series circuit relation andto an alternating current source, and holding means for said contactmembers controlled by said variable impedance device, the impedance ofsaid'device being relatively low when said contact members are in theopen position and relatively high when they are in the closed position,whereby said control relay is operated to deenergize said motor meansand saidholding meansis-acted up- 76 with said armature, a holdingwinding on said core, and circuit means connecting said windings ment ofsaid armature toward said core on operation of *said contact members tothe closed po-' sition, whereby said relay operates to deenergize saidmotor andsaid armature holding said linkage against movement, wherebysaid contact members are maintained in the closed position.

4. A circuit interrupter comprising, in combination, relatively movablecontact members for opening and cl'osing an electric circuit, operatingmeans for moving said contact members to the closed position, latchingmeans for holding said contact members in the closed position, a controlrelay for effecting the energization of said oper-- ating means, awinding for said control relay, an armature movable with said contactmembers, a winding operatively disposed with said armature in suchmanner as to have a minimum of inductance when said contact members areopen and a maximum of inductance when they are closed, auxiliary contactmeans disposed to be opened on movement of said contact members to theclosed position, contact means on said control relay connected to shuntsaid auxiliary contact means on energization of the relay winding, acircuit means for connecting said auxiliary contact means, said relaywinding and the variable inductance winding for energization to analternating current source, whereby said control relay is operated toenergize said operating means and, whereby said windings and operatingmeans are deenergized when said contact members are operated to theclosed position.

5. A circuit interrupter comprising, in combination, relatively movablecontact members for opening and closing an electric circuit, an electricmotor, linkage means interconnecting said contact members and saidmotor, latch means for engaging said linkage to hold said contactmembers in the closed position, said latch means being prevented fromoperatively engaging said linkage until said contact members are closed,means for biasing said latch means out of engagement with said linkagemeans, a control relay for effecting the energization of said motor, awinding for said relay, a core, a winding on said core, an armaturemovable relative to said core and connected to move with said latchmeans against the force of said biasing means, and circuit means forconnecting said windings in series circuit relation and for energizationto an alternating current source, whereby said motor is energized tooperate said contact members to the closed position, said armature isattracted to said core to cause said latch means to operatively engagesaid linkage and said relay winding is deenergized to an extentsuflicient to effect the deenergization of said motor.

ingmeans for moving said contact members to the closed position, a core,a winding for energizingsaid core, a main armature disposed to beattracted to said core on energization of said winding for holding saidcontact members closed, said main armature being movable toward saidcore only when said contact'members are moved to the closed position, anauxiliary armature disposedto be moved toward said core uponenergization of said winding and to be released therefrom on-movement ofsaid main armature to a position adjacent said core, contact meanscarried by said armature for effecting the energization of saidoperating means, and circuit means for connecting said winding forenergization to a current source.

7. A circuit interrupter comprising, in combination, relatively movablecontact members for opening and closing an electric circuit, an electricmotor, linkage means interconnecting said contact members and saidmotor, a core, a winding for energizing said core, a main armatureconnected to and movable only with said linkage means, said armaturebeing attracted toward said core on energization of said winding forholding said contact members closed, an auxiliary armature disposed tobe moved toward said core immediately upon energization'oi said windingand to be released therefrom on shunting of said core by movement ofsaid main armature, contact means carried by said auxiliary armature forcompleting an energizing circuit for said motor on energization of saidwinding and for opening said circuit when said auxiliary armature isreleased, and circuit means for connecting said winding for energizationto a source of direct current.

8. In a circuit interrupter, in combination, relatively movable contactmembers for opening and closing an electric circuit, an electric motorincluding a rotatable member disposed to move said contact members tothe closed position, an armature mechanically connected to said contactmembers and operable therewith, a winding cooperating with saidarmature, means for energizing said electric motor and said windingwhereby the latter assists the former in operating said contact membersto the closed position, means for deenergizing said motor on closure ofsaid contact members, and means for maintaining said winding energizedafter said motor is deenergized to hold said contact members in theclosed position.

9. Apparatus for moving a member from one position to an alternateposition comprising, in combination, electric motor means for operatingsaid member to said alternate position, a control relay and a windingtherefor for controlling the energization of said motor means, avariable impedance device disposed to operate together with said memberand a Winding therefor, and circuit means for connecting said windingsin series circuit relation and to an alternating current source, theimpedance of said device being relatively low when said member occupiessaid one position and relatively high when it occupies said alternateposition, whereby said control relay is operated to deenergize saidmotor means.

10. In a circuit interrupter, in combination, relatively movable contactmembers for opening and closing an electric circuit, a torque motor,

